About to make my first fuel tank

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by harry76, May 17, 2011.

  1. harry76

    harry76 New Member

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    Im building a fuel tank for my Villers beach cruiser. Ive been looking for steel for a while but didnt want to pay the ridiculous price for new steel. And most metal shops seem more interested in recycling their metal then selling cheaply to the public.

    Well i finally found some reasonably cheaped steel, it was free. It was the only bit he had and just gave it to me. Its got a little rust on it from sitting around. Obviously ill sand the rust off. And providing i can weld it with no leaks, and dont need tank liner (that stuff is dear), is it advisable to put some coating on the inside?

    Do you guys leave the inside of a fuel tank with bare metal? I guess if i painted it that could eventually come off, causing the same result as a rusty tank.

    Or does the fuel keep the rust at bay? The bike is a 2 stroke so dunno if that helps (oil in fuel)
     
  2. DaveC

    DaveC Member

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  3. bigbutterbean

    bigbutterbean New Member

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    If you don't line your tank, it will rust. I am thinking of one thing that might work, but not sure. Engine paint is fuel resistant. I don't know if it is strong enough to prevent rust, but it might be. I have thought recently that when making your own tank, painting the insides of the metal before welding might be a cheaper alternative to buying tank liner. But I could be wrong. Perhaps someone more experienced would be able to shed some light on that.
     
  4. harry76

    harry76 New Member

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    If you painted the inside of the tank, before welding it, wouldnt the heat from the welds peel the paint on the inside still leaving an area unprotected?. Not to mention flaky paint....

    Thanks Dave ill check the link
     
  5. BarelyAWake

    BarelyAWake New Member

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    TBH I never lined this tank: http://motorbicycling.com/f26/diy-tank-even-if-you-cant-17323.html and ofc the stock ones aren't lined either & as I use them frequently the fuel/oil mix keeps them completely corrosion free... So, if yer tryin' to save a few bucks on a bike yer gonna use ya can skip lining 'em and just check them frm time to time.

    I figure if rust ever does start to become a problem I'll clean it then *shrug* I will say if I were to build a show bike that sat most of the time I would most likely line the tank as an unlined, dry steel tank would no doubt rust w/a quickness ;)

    For storage of a dry, unlined tank, ofc ya can jus' hit the inside w/some WD40 or w/e...
     
    #5 BarelyAWake, May 18, 2011
    Last edited: May 18, 2011
  6. bigbutterbean

    bigbutterbean New Member

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    Well, engine paint withstands up to 500 degrees. A stick welder would probably get hotter than that, but I know tig welders are not as hot as stick welders.
     
  7. bigbutterbean

    bigbutterbean New Member

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    Also, I use kreem tank liner. It costs $20 a pint and I lined two stock tanks with one bottle. It is probably the least expensive tank liner sold, and is not hard to use. It sets up in an afternoon and dries in 24 hours.
     
  8. BarelyAWake

    BarelyAWake New Member

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    Molten steel pwns any paint every time... and TBH as good as some fuel resistant paints are - I'd not trust any of them for constant immersion, particularly with today's ethanol fuels.

    Which is also part of my reluctance to use a liner unless I have to, many are very good... but I dunno about the long term effects with higher concentrations of ethanol - they may well be fine, but it makes me nervous lol, it could make on heck of a mess :(
     
    #8 BarelyAWake, May 18, 2011
    Last edited: May 18, 2011
  9. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    I must concur with Barely here.....any welding on any steel would toast any paint period. Painting the inside of a gas tank....no good. Even the Kreem I used to line the inside of my aluminum top tube tank is feeling the effects of ethanol....that stuff is hard on any type of rubber or elastomeric materials so it seems. I would suggest an epoxy type resin for lining a tank and that stuff is rather expensive.

    Just leave it bare metal like most tanks in most vehicles and if you have a 2-stroke and are mixing the oil in your gas you have even less to worry about.....just do it and run a good fuel filter.

    dnut

     
  10. culvercityclassic

    culvercityclassic Well-Known Member

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    I have built a few tanks and had issues with tank liners, they were costly and the tank still leaked. The kicker was…I could not recoat the existing with-out removing the old. I was so pissed that I welded the tank leaks up with liner still in the tank. I did have to flush the burnt liner out and run a good filter.

    The best way is no liner IMO. It needs to be pressure checked for leaks and your good to go.
     
  11. harry76

    harry76 New Member

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    Sounds good to me. Bare metal it was. I wasnt keen on paying a lot for tankliner. I just wasnt sure if there was a cheaper way.
     
  12. Mr.B.

    Mr.B. Well-Known Member

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    Timely post!

    I also just finished building my first tank and I’m about to grid the welds smooth.

    What do method do the experienced recommend for leak testing? Just water?

    And what’s recommended to seal fittings like the petcock?

    I don’t mean to hijack your thread Harry, but this does seem related and hopefully helpful for you.

    Thanks,

    -Kirk
     
    #12 Mr.B., May 19, 2011
    Last edited: May 19, 2011
  13. harry76

    harry76 New Member

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    Ask away Mr.B..... valid questions and yes, helpful questions.

    Ill try and answer those questions until better advice comes along....

    The proper way to test a fueltank is pressure testing. Make a cap so that you can attach an air lead and pressurise the tank and submerse it in water and watch for the bubbles.

    And as far as sealing petcocks and fittings would be maybe thread tape or some fuel resistant silicone or something.

    I hope my answer is right and hope it helps. And good luck
     
  14. Tre_in_L.A.

    Tre_in_L.A. New Member

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    Especially if you're going to run a 2 cycle engine and pre mix in the fuel - don't bother coating. Just pressure test and you're good. If you insist or otherwise need to coat steel, I recommend Red Kote. I have had good results with KREEM as well but follow the directions to a T and let it cure in 70F average temps and for at least a week. Run filters in your fuel lines and check them often
     
  15. dmb

    dmb Active Member

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    4 or 5 lbs max or you might have a different looking tank than you hoped for.
     
  16. Elmo

    Elmo New Member

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    I did not use any liner. I had a few pin holes and just welded them up. No problems with any rust after a year or so. All the tanks I have seen on small engines are bare steel inside. Gasoline will find a leak without any pressure guarenteed. Just be sure the tank is dry when you weld up the leaks.
     
  17. tallcrown

    tallcrown New Member

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    Hi guys. The one thing that I do not think is cool is that Peanut tank that comes with most motor Kits. Everone has them. Does anyone know where they may sell a different tank that looks older? (like most of you make) seems like there would be a small market for one? or where can a guy buy an aftermarket phoney long tank that used to be on the Schwinn bikes from the 50's
    or...... Do you have any different Ideas for a tank Maybe hidden. I thought of mounting a Antique box on the back luggage rack and putting a hidden tank in there.
    Help.............
     

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